Need advice. 300 prc 230 reloading

[DeadNoise]

Need some advice. Reloading for 300 prc in AI AXSR.

Lapua brass.
215m primers
230 grain Atips
Retumbo.

During load development I make up 5 rounds in increments of .3 grains. Found a node at 78.3. Reload 10 more and it’s the same ES will go from 10.02 and SD of 3.73 to an ES averaging around 30 and SD to 17-22. Done this 4 times now and can’t seem to pinpoint my issue. Using a match master and double checking on an A&D scale.

 

[D̷e̷v̷i̷l̷D̷o̷c̷A̷Z̷]

Pre loading the Bipod EVERY time?

 

[DeadNoise]

i do yes, i thought that was my problem at first but i have confirmed that.

 

[rwest]

New brass, once fired? Annealing?

 

[DeadNoise]

Once fired.

 

[Rocketmandb]

There's a good chance it's just math. You're getting "lucky" with a 5-round group, then you go for the larger to validate, and the law of averages kicks in. Still, 17+ SD is pretty bad.

Questions:
- Are you annealing?
- Are you using a mandrel after sizing?
- Are you lubricating the case necks before seating?
- What velocity are you getting?
- What seating depth?

 

[howler]

Because powder nodes are made up…

 

[DeadNoise]

No on Annealing and mandrel
Seating depth is 2.872
2867-2908 velocity

 

[Rocketmandb]

Seating depth is 2.872

How far off the lands?

 

[DeadNoise]

.020

 

[Rocketmandb]

Sorry, one more question: how long is the barrel?

 

[DeadNoise]

26in

 

[Rocketmandb]

Recommendations:

1) Try another powder charge. Take what the larger groups are telling you over the smaller - try playing a little slower
2) Get a mandrel/die
3) Get some neck lube and apply either before mandrel or just before seating

 

[DeadNoise]

Recommendations:

1) Try another powder charge. Take what the larger groups are telling you over the smaller - try playing a little slower
2) Get a mandrel/die
3) Get some neck lube and apply either before mandrel or just before seating

Thank you. I’ve never got into the mandrel stuff. Any recommendations?

 

[Rocketmandb]

Thank you. I’ve never got into the mandrel stuff. Any recommendations?

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[DeadNoise]

Thank you, Appreciate the links, ill be ordering a kit